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At some point when you were a kid, you probably told yourself, "I'm not going to be anything like my mom and dad when I'm older …. I'm gonna be cool." Let me tell you … ah zuh pfeh.

But now that you're older, maybe you sometimes find yourself saying things like, “you know, when I was your age…” or, “money doesn't grow on trees!” And then you realize that you're kind of turning into your mom despite your best efforts. The good news is, you're not the only one who's ever worried about turning into their parents. The bad news is: when they grow up, people tend to share a lot more in common with their parents than they might expect.

It's often just a matter of time. Some of that stuff is just a normal part of aging. As you get older, your circadian rhythm shifts in a way that makes you get tired earlier and wake up earlier.

People also tend to become less concerned about having exciting new experiences and spend more time dwelling on nostalgic thoughts. So maybe we're all doomed to eventually start getting up at the crack of dawn and waxing poetic about the good old days. But you can also end up sharing all kinds of other things with your parents— everything from their personality traits to their career interests.

Which is why psychologists have spent a lot of time trying to figure out how likely people are to emulate their parents, and where exactly those similarities come from. When it comes to issues like abuse or alcoholism, the link isn't as straightforward, so we'll save that for another episode. But for things like personality traits, there's a good starting point in your genes.

Traits have different amounts of heritability, a statistic that describes how much of the variation in that trait among different people is determined by genetics. Height, for example, is about 70-80% heritable. So if you're really tall, odds are that genetics is a major factor, and that you have other tall people in your family.

But it's not entirely genetic. Things like your environment and circumstances play a role too, which is why two identical twins with the same genes sometimes turn out to be different heights. Personality traits also have different amounts of heritability, which is a big part of how you might end up similar to your parents.

To study personality, psychologists usually look at what are known as the Big 5 traits: extraversion, agreeableness, openness to experience, conscientiousness, and neuroticism. By looking at the similarities and differences between pairs of twins— some raised together and some raised apart— they've found that these psychological traits have heritabilities between 40-60%. That's lower than something physical, like height or hair color, but it means that genetics still has a pretty big influence on people's personalities.

So if you're just as stubborn as your father, or just as motivated as your mother, that could be the genetic influence on those big five traits. But parents influence kids through more than just genetics. You learn a lot of your behavior and traits from the people who raise you, regardless of whether you're biologically related to them.

That's known as the influence of shared environment, and it can affect things like overall intelligence, how religious you are, your political leanings, and what kinds of career interests you have. General intelligence, for example, might be affected by how stimulating your child's environment is. Things like having lots of reading material around and using complex sentences in conversation correlate with higher test scores.

When it comes to what kinds of careers you're interested in, both genetics and the shared environment seem to play a role— it's about 36% genetics and 10% shared environment. The effects of a shared environment also tend to fade over time. So if you're raised by someone other than your biological parents, you might be more like your caregivers when you're younger, but become a bit more like your biological parents once you get older.

Genetics and a shared environment can explain a lot, but they almost never account for everything. There's still plenty of room for individual variation and change in your attitudes and traits. There are also some things you just can't know about yourself until you become an adult ... like what kind of parent you'll be.

Research shows that people tend to adopt similar parenting styles to their own parents, like how much warmth they display or how strict they are when it comes to rules and chores. But waiting a while to have kids seems to reduce this effect. It's like older first-time parents have more opportunity to see other adults parent, which gives them more models for their own behavior.

So, there are lots of reasons you might be similar to your parents. But if there's anything you absolutely don't want to emulate, take heart that most of these influences max out at around 60%, even if you include the effects of a shared environment. Which means that the rest of the differences between people comes from other environmental factors … including what you choose for yourself.

You are your own person, and only you get to decide what that means. Thanks for watching this episode of SciShow Psych! If you are interested in learning more about the hidden connections between parents and their children, you can check out our video on whether trauma can be inherited. [OUTRO ♪].